1) Stability of metal properties: The chemical properties are relatively stable and can be maintained for a long time even if exposed to harsh environment for a long time. Iron, for example, can't be stored for a long time and is particularly prone to rust.
As money, it is often used. Under different circumstances, the acid-base environment is different, which requires that commodities as money must have chemical stability.
2) Strong ductility: Gold is soft and has good ductility. Because monetary units are large and small, and must be standard units. Therefore, this requires that the goods as money must be easy to cut, which is conducive to trade and non-governmental exchange.
On the other hand, gold is soft and has strong machinability. So gold is used for decoration, which in turn strengthens the importance of gold as a currency. Because if a commodity has no commodity attributes except monetary attributes, it will be easily replaced.
3) Scarcity: Gold production is relatively small, but it is not absolutely scarce. This moderate scarcity is also an important condition for the use of goods as money.
In human history, for a long time, there was no common currency as a trading medium, so the society could not develop well for a long time, until gold, as a common currency, greatly promoted social progress (interested people can look at the gold standard system, and a similar article of mine mentioned the application history of gold, and interested people can also look at it). Especially in the early days of the great voyage, gold was recognized as hard currency by most countries in the world, which greatly strengthened the role of gold.
From now on, the function of gold as a currency has been greatly weakened. Because of the appearance of paper money, gold is no longer directly used as a currency. However, with the advent of the electronic age, the importance of gold as a commodity (applied to industry) has been greatly strengthened, and the increase of this part of commercial attributes has in turn made up for the lack of monetary attributes. Therefore, gold is still a very important precious metal. Even now, the euro and the dollar are based on the strong gold reserves of their central banks. Therefore, gold remains the most important reserve currency. Once there is chaos in the world financial market, it must be gold that saves the global financial stability, and it is also gold that decides who speaks hard.